Heavy duty connector

ABSTRACT

Apparatus for facilitating engagement and disengagement in electrical connectors, particularly where large electrical loads are transmitted therethrough. A pivotal handle is disposed on the connector plug to protect the operator from electrical hazard and to maintain a relatively compact plug profile. Cooperation between the handle and the connector outlet creates a mechanical lock to preclude inadvertent disengagement and also achieves a relatively large mechanical advantage when disengagement is intended. Furthermore, this cooperation establishes an electrical interlock which interrupts power to the connector outlet whenever the mechanical lock ceases to exist.

United States Patent [1 1 Carissimi et al.

[4 1 Apr. 2, 1974 HEAVY DUTY CONNECTOR [75] Inventors: Vincent L.Carissimi, Fairfield;

Frank C. Jaconette, Jr., Trumbull, both of Conn.

[73] Assignee: Harvey Hubbell, Incorporated,

Bridgeport, Conn.

[22] Filed: Aug. 2, 1972 [21] Appl. No.: 277,467

[52] [1.8. CI. 200/50 B, 200/51.07, ZOO/51.09,

339/45 M [51] Int. Cl. H0lh 9/20, H0lh 33/46 [58] Field of Search 200/50B, 51.07, 51.08, ZOO/51.09; 339/45 B, 45 M, 75 R, 75 M, 91 R [56]References Cited UNITED STATES PATENTS 2,134,345 10/1938 Sheeran 339/45R 3,575,685 4/1971 Gley 339/45 M Bauroth 200/50 B Uberbacher et al.339/91 R Primary ExaminerDavid Smith, Jr. Attorney, Agent, orFirmWooster, Davis & Cifelli [57] ABSTRACT Apparatus for facilitatingengagement and disengagement in electrical connectors, particularlywhere large electrical loads are transmitted therethrough. A pivotalhandle is disposed on the connector plug to protect the operator fromelectrical hazard and to maintain a relatively compact plug profile.Cooperation between the handle and the connector outlet creates amechanical lock to preclude inadvertent disengagement and also achievesa relatively large mechanical advantage when disengagement is intended.Furthermore, this cooperation establishes an electrical interlock whichinterrupts power to the connector outlet whenever the mechanical lockceases to exist.

2 Claims, 3 Drawing Figures BACKGROUND OF THE INVENTION The presentinvention relates to an electrical connector and especially a heavy dutyconnector comprised of a plug and an outlet combination which includesprovi sions for facilitating engagement and disengagement therebetween.Hitherto, plugs have been structured to comply with the particularrequirements of various applications. Where the plug receives anelectrical cable in line with the male contact blades the profile heightit occupies above the outlet must include provisions for wiringterminals and a cable clamp. When such plugs are used in heavy dutyapplications where the cable connecting to the plug is quite large andinflexible, a very large cable bend radius is encountered in addition tothe profile height ofthe plug. Therefore, in such applications the plugis usually adapted to receive the cable perpendicularly to the malecontact blades and such plugs have become known as right angle plugs.

In heavy duty applications, a very tight fit exists between the malecontacts on the plug and the female contacts in the outlet andtherefore, a large force is required to effect engagement anddisengagement therebetween. This large force coupled with the cableinflexibility previously mentioned, causes particular difficulties whenright angle plugs are utilized. On engagement, a struggle is usuallyencountered in correcting any misalignment between the male contacts andthe female contacts due to the inflexible nature of the cable and itsorientation relative to the outlet. On disengagement any force appliedto the cable only results in a turning moment which tends to bind themale contacts within the female contacts and therefore the total forcemust be applied to the plug in line with the male contact blades.

Engagement and disengagement of most right angle plugs can only beaccomplished by gripping the plug directly to apply the necessary forcesthereto. Any alignment struggle encountered during engagement presents asafety hazard in that the operators hand or fingers may be burned by anelectrical are or may slip from the gripping surface to receive anelectrical shock. During disengagement, superfluous forces must beapplied perpendicular to the gripping surface in attaining a frictionalforce of sufficient magnitude to withdraw the male contacts from thefemale contacts.

Some right angle plugs are configured to provide a shield for protectingthe operators hand during engagement and a ledge to facilitate grippingduring disengagement. However, these plugs fail to remove the operatorshands from the zone of electrical hazard and achieve no mechanicaladvantage on disengagement.

In other right angle plugs, a permanently fixed handle is provided awayfrom the zone of electrical. hazard,

however, such handles result in a significant increase to SUMMARY OF THEINVENTION It is therefore, a general object of the present invention toprovide a heavy duty electrical connector which minimizes and obviatesthe disadvantages of the prior art.

It is a specific object of the present invention to provide a heavy dutyelectrical connector which facilitates engagement and disengagementbetween the plug and the outlet while affording safety from electricalhazard to the operator.

It is a more specific objectof the present invention to provide a heavyduty electrical connector having a plug on which a pivotal handle isaccessibly disposed without significantly increasing the overall profileheight of the plug.

It is another object of the present invention to provide a heavy dutyelectrical connector which utilizes a pivotal plug handle to develop amechanical advantage during disengagement.

It is still another object of the present invention to provide a heavyduty electrical connector which utilizes a pivotal plug handle toachieve a mechanical lock for precluding inadvertent disengagement.

It is a further object of the present invention to provide a heavy dutyelectrical connector which utilizes a pivotal plug handle to actuate anelectrical interlock for interrupting power to the outlet whenever amechanical lock ceases to exist.

These objects are accomplished in one form according to the presentinvention by disposing a handle on the plug to pivot about an axis whichperpendicularly intersects the axis along which the mating forces arecentered. The handle has arms extending from the pivotal axis and eacharm is specially configured about the pivotal axis to provide both alatch and a cam which pivot in unison with thehandle. The outlet isadapted to effect a mechanical lock upon mating with the latch andprovides a bearing surface against which'the cam acts to disengage theplug. An electrical switch is dis posed within the outlet and is trippedby a portion of the latch to energize the outlet in synchronism withattainment of the mechanical lock.

.. BRIEF DESCRIPTION OF THE DRAWING The manner in which these and otherobjects of the invention are achieved will be best understood byreference to the following description, the appended claims, and theattached drawing wherein:

FIG. 1 is a perspective view of a connector into which the improvementsof this invention have been incorporated and illustrating the plug andthe outlet in a disengaged arrangement;

FIG. 2 is a side elevational view thereof with the plug and the outletin a fully engaged arrangement and having portions cut away toillustrate the cooperation existing between the plug, the handle, andthe outlet, and

FIG. 3 is a side elevational view thereof with the plug and outlet in anintermediate arrangement to illustrate the correlated motion of the camand the latch on the handle.

DESCRIPTION OF THE PREFERRED EMBODIMENT Turning now to the drawing, aheavy duty electrical connector 10 incorporating the improvements ofthis invention is illustrated in FIGS. 1 3. As illustrated in FIG. 1,the connector generally consists of a plug 12 and an outlet 14 whichmate along a common axis to effect an electrical connection between apower source (not shown) and an electrical apparatus (not shown).

The outlet 14 is contained in an outlet box 16 wherein a female contactholder 18 is mounted by any suitable means such as screws (not shown).The female contact holder 18 passes through an opening 20 in a coverplate 22 which is secured by screws 24 to the outlet 14. Female contacts(not shown) are disposed within slots 26 of the female contact holder 18and are connected to a source of electrical power within the outlet 14by any suitable means, such as wires (not shown).

Male contact blades 28 extend from a male contact holder 30 which'issecured to the plug 12 by any suitable means, such as screws (notshown). Terminal means (not shown) are disposed on each blade 28 withinthe plug 12 for securing to the conductors of an I electrical cable 32which enters into the plug 12 perpendicularly to the blades 28. Theblades 28 slidably engage through the slots 26 and into the femalecontacts of the outlet 14 to effect the electrical connection which issustained through contact forces directed perpendicularly across theblades 28 by the female contacts.

A handle 34 is pivotally secured across the plug 12 and is utilized toeffect both engagement and disengagement between the plug 12 and theoutlet 14. The pivotal axis of the handle extends through the plug 12and intersects perpendicularly with a transfer axis which is disposedparallel to the common axis. Forces applied along the transfer axis aredistributed over the plug 12 to result in balanced turning moments aboutany axis in a plane perpendicularto the common axis. On the handle 34,arms 36 extend perpendicularly from the pivotal axis at each side of theplug 12 and a gripping bar 38 interconnects the-arms 36 across the plug12. About the pivotal axis, each arm 36 is configured to have'both alatch 40 and a cam 42. Where desirable, a single latch 40 and a singlecain 42 can be utilized to simplify fabrication of the handle 34. Insuch an arrangement, the latch 40 and cam 42,may be disposed on the samearm 36 or separately on different arms 36. A slot 44 is disposed in thecover plate 22 of the outlet 14 to receive each latch 40 upon engagementbetween the plug 12 and the outlet 14.

Full engagement of the plug 12 into the outlet 14 is shown in FIG. 2where the outlet box 16 is secured to a bulkhead 46 by any suitablemeans, such as screws 48. The latches 40 rotate in direct response tothe pivotal motion of the handle 34 and during engagement, cooperatewith the outlet 14 to develop a mechanical lock between the plug 12 andthe outlet 14. This cooperation consists of the latches 40 being rotatedinto the slots 44 and disposed behind the cover plate 22. The grippingbar 38 is compatibly configured to lie flat against the plug 12 in thefully engaged arrangement and has a portion overhanging the plug 12 topresent a gripping lip 50.

An electrical switch 52 is disposed within the outlet box 16 and isoperative througha spring biased push button 54 to make or break anelectrical contact (not shown). The switch 52 is precisely located tocooperate with the handle 34 in establishing an electrical interlockwhich interrupts the power supplied to the outlet l4 whenever themechanical lock ceases to exist due to rotation of the latches 40 frombehind the cover plate 22. Any cooperating means can be utilized betweenthe switch 52 and the handle 34, such as actuating the push button 54through a roller 56 and a pivot link 58 combination with either latch40..This cooperating means is inaccessibly located within the outlet 14and can only be reached through one of the slots 44 in the cover plate22, so as to make unintended operation of the electrical interlock mostdifficult. The contact of the switch 52 can be utilized in anyelectrical circuit means to interrupt the power supplied to the outlet14, such as to wire the outlet 14 directly through the contact.

The cams 42 rotate in direct response to the pivotal motion of thehandle 34 and have an increasing eccentricity forcounterclockwiserotation of the handle 34. On disengagement, each cam 42cooperates with the outlet 14 to develop separating forces between theplug 12 and the outlet 14, as illustrated in FIG. 3. Because themechanical lock precludes separation between the plug 12 and the outlet14, this cooperation does not occur until the latches 40 have beenrotated from behind the cover plate 22. 97

In use the handle 34 on the plug 12 operates to facilitate bothengagement and disengagement between the plug 12 and the outlet 14. Onengagement, the operator grips the handle 34 around the gripping bar 38which pivots to a location well removed from the zone of electricalhazard. After aligning the blades 28 with the slots 26, a force toeffect engagement between the malecontact blades 28 and the femalecontacts is then applied along the transfer axis of the plug 12. Asengagement proceeds, the cams 42 on the handle 34 bear on the coverplate 22 of the outlet 14, as illustrated in FIG. 3. Thereafter,engagement is continued while rotating the handle clockwise to maintainaclearance between the cams 42 and the cover plate 22, as illustrated inFIG. 2. Engagement is completed when the latches 40 on the handle 34have been directed into the slots 44 of the cover plate 22 and thehandle 34 is rotated flat against the plug 12 with no separationexisting between the plug 12 and the outlet 14. During the final stagesof engagement, the roller 56 interfaces with one of the latches 40 totrip the switch 52 and thereby actuate the power supplied to the outlet14. Due to the compatible configuration existing therebetween, thegripping bar 38 of the handle 34 lies flat against the plug 12 in thefully engaged arrangement and therefore, the overall profile of the plug12 is not significantly affected by the addition of the handle 34. Also,the mechanical lock created by the disposition of the latches 40 behindthe cover plate 22 precludes any disengagement until the handle 34 isrotated sufficiently in a counterclockwise direction.

On disengagement, the operator pulls against the gripping lip 50 of thehandle 34 which thereby causes the handle 34 to rotate in acounterclockwise direction and results in departure of the latches 40from the slots 44. During this departure, the roller 56 on the switch 52ceases to interface with the one latch 40 and therefore the spring biason the push button 54 trips the switch 52 to electrically deactuate theoutlet 14. After an initial rotation of the handle 34, the gripping bar38 is grasped to-facilitate rotation of the handle 34. Thecounterclockwise rotation of the handle 34 is continued with the cams 42coming to bear against the cover plate 22, as illustrated in FIG. 3, toforce a separation between the plug 12 and the outlet 14. Rotation ofthe handle 34 continues until the arms 36 of the handle 34 are alignedparallel with the transfer axis, at which point the eccentricity of thecams 42 achieves a maximum. Disengagement is then completed without anyfurther rotation of the handle 34, by pulling the grip ping bar 38 alongthe transfer axis with sufficient force to accomplish completeseparation. During the complete disengagement sequence, the operatorshand is at all times removed from the zone of electrical hazard. Initialdisengagement is accomplished through the earns 42 which cooperate withthe arms 36 to achieve a mechanical advantage. In magnitude themechanical advantage is equal to the length of a single arm 36 from thepivotal axis, divided by the eccentricity of a single cam 42 from thepivotal axis. Because the electrical connection is effected throughcontact forces perpendicularly across the blade 28, the disengagingforce is greatest during the initial separation of the plug 12 from theoutlet 14, and therefore, the mechanical advantage is utilized duringthe most difficult phase of disengagement.

Those skilled in the art should readily appreciate that the heavy dutyconnector embodied by this invention provides the operator with safetywhile facilitating both engagement and disengagement between the plugand the outlet. Also, the handle utilized does not significantly affectthe overall profile of the plug and yet is readily accessible fordisengagement during which it achieves a considerable mechanicaladvantage. Furthermore, the handle cooperates with the outlet toestablish both a mechanical lock and an electrical interlock, with thelatter operating to interrupt the power supplied to the outlet when theformer ceases to exist.

It should be understood that the present disclosure has been made onlyby way ofexample and that numerous changes in details of constructionand the combi- 6 nation or arrangement of parts may be resorted towithout departing from the true spirit and scope of the invention andtherefore, the presentdisclosure should be construed as illustrativerather than limiting. What we claim is:

1. In an electrical connector apparatus comprising;

an outlet including female contacts and an electrical switch;

a plug including male contacts, said plug and said outlet mating along acommon axis with said male contacts slidably engaging said femalecontacts to effect the electrical connection; and

a pivotal handle securing to said plug about a pivotal axisperpendicular to-said common axis, said handle including a-latch and anarm, said latch being pivotal about said pivotal axis to cooperate withsaid outlet and said electrical switch in establishing a mechanical lockand an electrical interlock between said plug and said outlet, saidelectrical interlock interrupting electrical power to said outletwhenever said mechanical lock ceases to exist.

2. The apparatus of claim 1 wherein said plug has a transfer axisparallel to said common axis and forces applied along said transfer axisare distributed over said plug to result in balanced turning momentsabout any axis in a plane perpendicular to said common axis, saidpivotal axis being perpendicular to said transfer axis; said handleincludes a gripping bar extending across said plug, said grippingbarbeing configured to lie flat against said plug and having nosignificant affect on the overall profile height of said plug; a portionof said gripping bar overhangs said plug, said portion establishing agripping lip to facilitate the use of said handle during disengagement;said arm includes a cam, said cam being rotatable about said pivotalaxis to bear against said outlet in developing separating forces betweensaid plug and said outlet.

1. In an electrical connector apparatus comprising: an outlet includingfemale contacts and an electrical switch; a plug including malecontacts, said plug and said outlet mating along a common axis with saidmale contacts slidably engaging said female contacts to effect theelectrical connection; and a pivotal handle securing to said plug abouta pivotal axis perpendicular to said common axis, said handle includinga latch and an arm, said latch being pivotal about said pivotal axis tocooperate with said outlet and said electrical switch in establishing amechanical lock and an electrical interlock between said plug and saidoutlet, said electrical interlock interrupting electrical power to saidoutlet whenever said mechanical lock ceases to exist.
 2. The apparatusof claim 1 wherein said plug has a transfer axis parallel to said commonaxis and forces applied along said transfer axis are distributed oversaid plug to result in balanced turning moments about any axis in aplane perpendicular to said common axis, said pivotal axis beingperpendicular to said transfer axis; said handle includes a gripping barextending across said plug, said gripping bar being configured to lieflat against said plug and having no significant affect on the overallprofile height of said plug; a portion of said gripping bar overhangssaid plug, said portion establishing a gripping lip to facilitate theuse of said handle during disengagement; said arm includes a cam, saidcam being rotatable about said pivotal axis to bear against said outletin developing separating forces between said plug and said outlet.